2株番茄早疫病拮抗菌的分离筛选与拮抗作用研究

摘要

[目的]从新疆昌吉、焉耆、喀什、乌苏、吉木萨尔五地多年种植番茄的农田土壤样品,进行拮抗菌的筛选,选取对番茄早疫病菌(Alternaria solani)有具有较强抑菌活性的菌株.[方法]采用平板分离培养法从加工番茄的根际土壤中分离拮抗菌,平板对峙培养实验进行初筛和复筛,根据培养特征、菌体形态及16S rDNA系统发育分析进行初步鉴定,显微观察法观察拮抗菌对病原菌菌丝生长的拮抗作用,盆栽法测定相对防效.[结果]共分离得到90株细菌菌株,初筛得到对番茄早疫病菌有明显拮抗作用的细菌,复筛选取2株抑制作用显著的细菌(J2-2、J2-4),并初步鉴定为芽孢杆菌属(Bacillus)的萎缩芽孢杆菌(Bacillus atrophaeus)和枯草芽孢杆菌(Bacillus subtilis)的近似种;显微镜下观察到2株拮抗菌的发酵液对番茄早疫病菌丝有明显的致畸作用;在盆栽试验中,拮抗菌发酵液对番茄早疫病菌的相对防效可达到35％以上.[结论]筛选到的2株拮抗菌对番茄早疫病菌表现出较好的拮抗作用,对番茄早期病害的生物防治具有一定的应用价值.%[Objective] Screening for bacteria againstAlternaria solanio tomato from rhizosphere of processing tomato.[Method] Isolating antagonistic bacteriafrom rhizosphere of processing tomatoby culture on medium plate,preliminary screening and second screening are carried on by paired culture,preliminary identification is based on morphological characteristic,phylogenetic analysis of 16S rDNA,antagonistic effect of fermentation broth against mycelium ofA.solani is observed under microscope,relative control effect of fermentation brothof antagonistic bacteria is observed by pot incubation test.[Result] 90trains of antagonisticbacteria have been isolated,from them,3 strainsofbacteriahave been screened by preliminary screening while 2 strains by second screening with obvious antagonistic effect (J2-2,J2-4),and then the two stains were preliminary identified as allied species ofBacillus atrophaeus andBacillus subtilis,teratogenic effect of fermentation brothagainst pathogenic mycelium has been observed under microscope,the relative control effect of fermentation broth has been determined above 35％ in pot incubation test.[Conclusion]The result shows that the two isolates with significant antagonistic effect toA.solani could provide potential solution for biological control of early blighttomato.